In recent years, development of a display device (organic EL display) using an organic electroluminescence (EL) element as a light emitting element is progressing. In this display device, for example, an organic layer including at least a light emitting layer and a second electrode (upper electrode) are formed on a first electrode (lower electrode) formed so as to be isolated for each pixel. In the organic layer, a charge injection layer is further formed between the first electrode and the light emitting layer. Furthermore, for example, each of a red light emitting element that emits red light, a green light emitting element that emits green light, and a blue light emitting element that emits blue light are each disposed as a sub-pixel, and these sub-pixels constitute one pixel. Alternatively, a red light emitting element obtained by combining a light emitting element that emits white light and a red color filter, a green light emitting element obtained by combining a light emitting element that emits white light and a green color filter, and a blue light emitting element obtained by combining a light emitting element that emits white light and a blue color filter are each disposed as a sub-pixel, and these sub-pixels constitute one pixel. In addition, in each of the light emitting elements, an organic layer is patterned and has an end face.
By the way, when the end face of the organic layer comes into contact with the second electrode formed on the organic layer, a current flows not only between a top face of the organic layer and the second electrode but also between the end face of the organic layer and the second electrode. Note that the current in this case is not a recombination current but a conduction current for the most part. In addition, flowing of a current between the end face of the organic layer and the second electrode causes brightness variation among pixels particularly at the time of low gradation, leading to deterioration in display image quality. A structure in which an end face of an organic layer is filled with an insulation layer containing SiO2 such that the end face of the organic layer is not exposed to a second electrode has been proposed (refer to, for example, Japanese Patent Application Laid-Open No. 2005-276667).